ARRL Propagation Bulletin ARLP032 (1999)

SB PROP @ ARL $ARLP032
ARLP032 Propagation de K7VVV
ZCZC AP32
QST de W1AW
Propagation Forecast Bulletin 32 ARLP032
From Tad Cook, K7VVV
Seattle, WA August 6, 1999
To all radio amateurs
SB PROP ARL ARLP032
ARLP032 Propagation de K7VVV
Solar flux and sunspot numbers increased again last week, with
average sunspot numbers up over 52 points to 219.3 and average solar
flux up over 27 points to 206.9. The solar flux of 216.3 on Sunday
is a new high for the current cycle, besting the June 30, 1999
record of 209.5 by almost 7 points. The last time solar flux was
higher was in cycle 22, when the February 29, 1992 number was 218.
To see recent trends graphically, check the websites
http://www.wm7d.net/hamradio/solar/ or http://www.dxlc.com/solar/.
If it weren't for a major geomagnetic storm, this activity would
mean better propagation on the high end of the HF bands. Last
Friday was a really rough day geomagnetically, with a planetary A
index of 36. But this made things interesting for VHF operators who
took advantage of an aurora
For this weekend, look for a solar flux of 170, 165 and 160 for
Friday through Sunday, and moderate geomagnetic conditions with a
planetary A index of 10, 8 and 8.
Beyond the weekend, look for a solar flux below 10 by August 10,
with the current numbers bottoming out around 135 August 11-14.
Flux values should be up to 150 again around August 18, 170 by
August 21, and 200 around August 25-29.
Watch for disturbed geomagnetic conditions returning around August
18.
Sunspot numbers for July 29 through August 4 were 226, 218, 220,
267, 210, 217 and 177 with a mean of 219.3. 10.7 cm flux was 202.4,
205.9, 200.6, 216.3, 212.5, 210.7 and 200.1, with a mean of 206.9,
and estimated planetary A indices were 10, 36, 21, 9, 9, 8 and 11,
with a mean of 14.9.
Path projections for this week are from the New York City area.
To Europe, 80 meters 2330-0530z, 40 meters 2230-0700z, 30 meters
2030-0900z, 20 meters nearly around the clock, best 0000-0330z,
weakest 1100-1700z, 17 meters 1300-0200, getting stronger later in
that period, 15 meters possibly 1600-2300z.
To Southern Africa, 80 meters 2330-0430z, 40 meters 2300-0500z, 30
meters 2230-0530z, 20 meters 2030-0630, with a weak period around
0330z, 17 meters 1900-0200z, 15 meters 1700- 0130z.
To the Caribbean, 80 meters 2300-1030z, 40 meters 2100-1230z, 30
meters all hours, best 0030-0930z, 20 meters all hours, best
0000-0930z, 17 meters all hours, best 0000-0400z, 15 meters
1300-0300z.
To South America, 80 meters 0000-0930z, 40 meters 2300-1000z, 30
meters 2230-1100z, 20 meters 2100-1230z, 17 meters 1000- 0500z, best
late in the session, 15 meters 1330-0300z.
To Australia, 80 meters 0700-1030z, 40 meters 0630-1030z, 30 meters
0630-1100z, 20 meters 0500-1300z, 17 meters 0300- 0730z, 15 meters
0230-0530z, 12 meters possibly 0200-0300z.
To Japan, 30 meters 0930-1100z, 20 meters 0730-1230z, 17 meters
1430-1600z.
NNNN
/EX